Ep 5. 24 Hours on Earth - Night

As the sun sets and its great heat and light are extinguished, a nighttime world wakes, full of characters who have carved a niche in the darkness. Dusk sees three million wrinkled lipped bats swirl out of their cave to feast on nocturnal insects. A sea dragon courts a female in the dying light of the Australian reef. And as darkness takes hold, a pride of lions decide to go hunting.